Glutathione S-transferases (GSH-Tr's) catalyze the nucleophilic attack of glutathione (GSH) on the electrophilic centers of hydrophobic compounds or bind them as nonsubstrate ligands. They are the major binding protect for bilirubin in the hepatocyte. These enzymes are low in fetal liver but increase rapidly post-partum. They can be induced in rat liver to almost five fold over control by injection with phenobarbital, 3-methylcholanthrene and trans-Stilbene oxide. Other organs such as lung, heart, spleen, also have these GSH-Tr's but without the GSH peroxidase (non Se-dependent) activity which the liver and other organs GSH-Tr's have. The GSH-Tr's also play a significant role in the biosynthesis and regulation of prostaglandins, prostacyclins, thromboxanes and leucotrienes. However, nothing is known about this system at the DNA level. This proposal intends to contribute to the biochemical genetical aspects of GSH-Tr's. We like to purify each of the liver GSH-Tr's to homogeneity, raise specific antibodies and use in vitro translation assay to partially purify the mRNA's for liver GSH-Tr's followed by cloning into E. coli via pBR322. They will be used as specific probes: (1) to look into the genomic organization of GSH-Tr's in different organs and tissues by Southern blotting experiments, cloning and sequencing, (2) to investigate the apparent tissue specific expression of GSH-Tr's (with reference to the GSH peroxidase activity) using molecular cloning and DNA, mRNA sequencing techniques, (3) to study the mechanism of induction og GSH-Tr's by using cloned mRNA sequences to detect any possible changes in DNA structure or RNA level upon induction, (4) to compare genomic DNA organization of GSH-Tr's in different mammalian species, (5) to study the heterospecific expression of these cloned mRNA sequences in E. coli in order to design a general system for heterospecific expression. For longer term objectives, we hope to correlate gene organization and expression of GSH-Tr's to a given individual's susceptibility to chemically induced carcinogenesis. We will also pay special attention to the possible involvement of movable genetic elements in the control of gene expression of these GSH-Tr's.